两种厄尔尼诺类型期高原地区大气环流的对比分析

Analysis of Contrast between Two Atmospheric Circulations at Plateau Section during the Period of El-Nino

本文利用NCEP/NCAR再分析资料,分析了增温区域不同的两类El-Nino事件各阶段的特征,及其次年夏季高原地区的风场、温度场以及高原上空的南亚高压的高度场分布特征。结果表明:对风场环流的不同影响主要表现在:从垂直剖面图来看EP型整体都是东风增强,而CP型在对流层的中下层为西风增强,上层为东风增强;200h Pa风场EP型高原上空为异常东风,而CP型为一异常切变线,北边异常东北风,南边异常东南风;500h Pa风场EP型表现为异常东北风,CP型为异常东南风。对温度场的不同影响主要表现在:EP型在高原上空对流层中层和高层各有一个负异常中心,而CP型只在中层有一个负异常中心;对南亚高压的不同影响主要表现在:EP型南亚高压中心位置偏东南,而CP型南亚高压中心位置则偏北。

Using the NCEP/NCAR reanalysis data, this paper analyzes the characteristics of different stages of the two E1- Nino events in different warmer regions, and the distribution characteristics of the wind field, temperature field and the height field of the South Asia high pressure which is above the plateau are also analyzed. Results show that the different effects of wind circulation are mainly manifested in： easterly wind enhances as a whole from the vertical profile of EP type, but to CP type, westerly wind enhances in the middle and lower classes of troposphere, and easterly wind also enhances in the upper class. On 200hPa wind field, over the plateau of EP type is abnormal wind, but CP type is an abnormal shear line ; on the north side dis- plays anomaly northeaster; on the south it shows southeast wind anomaly ; On 500 hpa wind field, EP type characterizes by ab- normal northeaster, but type CP shows abnormal for southeast wind. The different effects on the temperature field are mainly manifested in： EP type each has a negative anomaly center in the mid and top troposphere over Plateau, but CP type only has a negative anomaly center in the middle troposphere. The different impacts on the South Asia high is mainly manifested in： EP SAH center location tends to Southeast, but CP SAH center location tends to north.